The present invention relates to a calibration apparatus for determining the tension of metal components, for example, bolts, studs, nuts, metal fasteners, and the torque of rotating, fastener tightening tools. More particularly, the present invention discloses a calibration apparatus which simultaneously, contemporaneously, and accurately measures tension and torque for metal components and tools placed under stress.
Industrial strength fasteners, such as metal bolts and their accompanying nuts, undergo significant stress during the bolt/nut installation process. This stress occurs as the nut is turned around the threads of the bolt, causing tension within the bolt, as the bolt stretches and compresses its head against the nut. As it is rotated through the nut, the bolt develops increasing tension as a result of the torque applied by the bolt tightening tool. It is therefore necessary to accurately calibrate the bolt tension and the torque required in order to obtain maximum tightening of the bolt, without breakage, thus ensuring that the proper fastener is being used for a given job.
All prior calibration apparatus and techniques involve calibrating the torque of the tightening tool required to establish the desired tension and then proceeding with a separate operation to calibrate the tension of the fastener/bolt as it relates to the calibrated torque of the tightening tool. This two step process is not only cumbersome and a waste of time, but also results in inaccurate results. There is currently no apparatus which calibrates both metal component tension and the torque required to achieve that tension, simultaneously and contemporaneously. And this apparatus does so easily, quickly, and efficiently.